Nippondenso Co., Ltd.

Kiyotaka Sasaki

Takeshi Matsui

Noboru Yamamoto

Yasuo Ito

Ryosuke Tachi

Masakuni Tsujimura

Kouichi Kato

Katsunori Iwamoto

Hideji Tani

Kenji Hashimoto

An ignition system for internal combustion engines comprises means for generating an ignition signal in synchronism with the revolution of an internal combustion engine and an ignition circuit device for interrupting a primary current of an ignition coil in accordance with the ignition signal. The ignition circuit device includes an ignition monitor signal producing circuit for producing an ignition monitor signal which circuit operates to set the ignition monitor signal at the time of starting the energization of the ignition coil and thereafter to reset the ignition monitor signal at a subsequent predetermined timing, whereby the ignition circuit device operates, in accordance with the pulse width and the set and reset conditions of the ignition monitor signal, to decide whether the operation of the ignition circuit device is normal or abnormal, to control to generate a predetermined amount of ignition energy, and to prevent erroneous generation the ignition monitor signal due to a noise or the like.

Ignition system for internal combustion engines

An apparatus for controlling the spark timing of an internal combustion engine comprises means for generating a reference position signal with reference to a predetermined engine crankshaft position; waveform shaping means for generating a reference pulse signal having a leading edge advanced with respect to the predetermined crankshaft position as a function of the engine speed, in accordance with the reference position signal; means for detecting the amount of engine load; means for detecting the rotational speed of engine; means for computing a period of time elapsed from the leading edge of the reference pulse in accordance with the detected engine load and engine speed in order to establish a spark timing; means for detecting the variation of period between the leading edge and trailing edge of the reference pulse in relation to each cylinder; and means for correcting the computed period of time in accordance with the detected variation and for generating an output signal causing ignition to occur after the elapse of corrected period of time. The computer estimate spark timing for each cylinder is corrected in accordance with the variation of a period between the leading edge and the trailing edge of the reference pulse, resulting in an optimum spark timing without variation among individual cylinders.

Method and apparatus for controlling spark timing in internal combustion

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Nagoya, Japan

Kiyotaka Sasaki